/*
 * @Author: sjr
 * @Date: 2021-01-24 14:19:58
 * @LastEditTime: 2021-01-24 14:29:13
 * @LastEditors: sjr
 * @Description: 描述
 * @FilePath: \leetcode\111.二叉树的最小深度.js
 */
/*
 * @lc app=leetcode.cn id=111 lang=javascript
 *
 * [111] 二叉树的最小深度
 */

// @lc code=start
/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {TreeNode} root
 * @return {number}
 */
var minDepth = function(root) {
  if(!root) return 0
  if(!root.left && !root.right) return 1
  if(!root.left) return minDepth(root.right) + 1
  if(!root.right) return minDepth(root.left) + 1
  return Math.min(minDepth(root.left)+1, minDepth(root.right)+1)
};
// @lc code=end

